Java XPath Get getListValue(Node node, XPathExpression expression)

Description

Evaluates the XPath expression in the specified context and returns the found items as a List.

License

Open Source License

Parameter

Parameter	Description
node	the XML document to evaluate
expression	the compiled XPath expression

Return

the list of elements found

Declaration

public static List<String> getListValue(Node node, XPathExpression expression) 

Method Source Code

//package com.java2s;
/*//from w  w  w .j a  va 2 s  .com
 * MIT License
 * Copyright (c) 2016 Estonian Information System Authority (RIA)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.xpath.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Main {
    /**
     * Evaluates the XPath expression in the specified context and returns the found items as a List.
     *
     * @param node       the XML document to evaluate
     * @param expression the compiled XPath expression
     * @return the list of elements found
     */
    public static List<String> getListValue(Node node, XPathExpression expression) {
        try {
            NodeList nodeList = (NodeList) expression.evaluate(node, XPathConstants.NODESET);
            List<String> list = new ArrayList<String>(nodeList.getLength());
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node item = nodeList.item(i);
                list.add(item.getFirstChild().getNodeValue());
            }
            return list;
        } catch (XPathExpressionException e) {
            // Try to evaluate in string context:
            String value = getStringValue(node, expression);
            if (value != null) {
                List<String> list = new ArrayList<String>(1);
                list.add(value);
                return list;
            }
            return Collections.emptyList();
        }
    }

    /**
     * Evaluates the XPath expression in the specified context and returns whether such element was found.
     *
     * @param node       the XML document to evaluate
     * @param expression the compiled XPath expression
     * @return <code>true</code> if the given expression evaluates to an existing element in the given node,
     * <code>false</code> otherwise
     */
    public static boolean evaluate(Node node, XPathExpression expression) {
        try {
            Boolean result = (Boolean) expression.evaluate(node, XPathConstants.BOOLEAN);
            return result != null && result;
        } catch (XPathExpressionException e) {
            return false;
        }
    }

    /**
     * Evaluates the XPath expression in the specified context and returns the found element as a String.
     *
     * @param node       the XML document to evaluate
     * @param expression the compiled XPath expression
     * @return the element if it was found, or null
     */
    public static String getStringValue(Node node, XPathExpression expression) {
        try {
            return (String) expression.evaluate(node, XPathConstants.STRING);
        } catch (XPathExpressionException e) {
            return null;
        }
    }
}

Related

1. getFirstByXPath(Object obj, String xpathExpression)
2. getFullXPath(Node n)
3. getHtmlXPath()
4. getInt(Object node, XPathExpression expression)
5. getLatestVersion(String tempDir, String url, String groupId, String artifactId, String version)
6. getListValue(String targetDoc, List xpathExps, String encoding)
7. getMessage(XPathExpressionException e)
8. GetMobivateSessionId()
9. getNameBasedXPath(Node n, boolean includeCurrent)